Impact of adjuvant therapy on survival outcomes in resected gallbladder cancer: a systematic review and meta-analysis

Background: Gallbladder cancer (GBC) is the most common malignancy of the biliary tract and ranks as the fifth most prevalent cancer of the digestive system. Despite surgical resection, the prognosis for GBC remains dismal, marked by high recurrence rates and poor overall survival (OS). This meta-analysis investigates the impact of adjuvant therapies-including chemotherapy (CT), radiotherapy (RT), and chemoradiotherapy (CRT)-on the prognosis of resectable GBC, aiming to elucidate their clinical benefits. Methods: A thorough search of PubMed, Embase, and Web of Science databases was conducted up to April 2024. Studies assessing the effects of adjuvant therapies on OS and disease-free survival (DFS) in patients with resectable GBC were included. Statistical analyses were performed using STATA 17.0 software, with random-effect models employed to address heterogeneity. Results: The meta-analysis included 23 studies encompassing 36,214 patients. Adjuvant therapy was significantly associated with improved OS [hazard ratio (HR), 0.72; 95% confidence interval (CI): 0.66-0.78]. Specific types of adjuvant therapy showed distinct benefits: CT (HR, 0.80; 95% CI: 0.72-0.88), RT (HR, 0.76; 95% CI: 0.65-0.88), and CRT (HR, 0.56; 95% CI: 0.47-0.67). Subgroup analysis revealed a greater benefit in high-risk patients, including those with more severe tumor-node-metastasis (TNM) staging, R1 resection, and older age (HR, 0.62; 95% CI: 0.50-0.76). Conclusions: Adjuvant therapy significantly improves OS in patients with resectable GBC, with CRT offering the most substantial benefit. These results advocate for the inclusion of adjuvant therapy in treatment regimens, particularly for high-risk patients, and underscore the necessity for ongoing research to refine therapeutic approaches.